Cake mix and acyl lactylic acid additives employed therein



United States Patent 3,146,110 CAKE MIX AND ACYL LACTYLIC ACID ADDI-TIVES EMPLOYED THEREEN Bruce D. Buddemeyer, Overland Park, Kans., andJohn Robert Moneymaker, Kansas City, Mo., assignors to The PaniplusCompany, Kansas City, Mo., :1 corporation of Missouri No Drawing.Original application Dec. 28, 1961, Ser. No. 162,927. Divided and thisapplication Jan. 30, 1963, Ser. No. 271,534

3 Claims.

The present invention relates to acyl monohydroxy monocarboxylic acidsand salts thereof which possess unique properties as emulsifiers andmodifiers of protein and starch materials; to methods of making suchacids and salts; and to improved baked leavened products and ingredientstherefore containing such acids and salts.

This application is a division of our co-pending application Serial No.162,927, filed December 28, 1961.

It is an object of the present invention to provide new and useful acylmonohydroxy monocarboxylic acids and salts thereof.

Another object of the present invention is to provide methods for makingacyl monohydroxy monocarboxylic acids and salts.

Still another object of the present invention is to provide improvedbaked leavened products and ingredients therefor containing acylmonohydroxy carboxylic acids and salts thereof.

Other objects of the present invention will in part be obvious and willin part appear hereinafter.

The new and useful acyl monohydroxy monocarboxylic acid compositions ofthe present invention are acyl lactylic acids and salts corresponding tothe general formula:

RCO (OCHCHgCO OZ wherein RC0 is a member selected from the groupconsisting of acyl radicals of fatty acids containing 16 to 24 carbonatoms, and mixtures thereof; Z is a cation; and n is a numberrepresenting the average number of lactyl groups, i.e., (OCHCH CO),present per molecule of the composition, the value of n being less than1 and preferably between about 0.3 and 0.9.

The cation Z in the above formula may be selected from the groupconsisting of hydrogen, alkali metals, alkaline earth metals, ammoniaand aluminum. Among the preferred alkali metal cations may be mentionedsodium and potassium, while preferred alkaline earth metal cationsinclude calcium and magnesium.

Compounds satisfying the above formula are referred to herein as acyllactylic acid compositions.

Although acyl polylactylic acid compositions containing an averagenumber of lactyl groups per mole of greater than 1 are known, asindicated, for example in U.S. Patent 2,733,252, it should be understoodthat the materials disclosed herein, both in free acid form and in saltform, are different from the polylactylic acids and salts having an 11value greater than 1.

For example, the materials of the present invention containing anaverage of less than 1 lactyl group per mole cule are more functionaland provide greater utility than compounds in which the average numberof lactyl groups per molecule is greater than 1. This is surprising,inasmuch as the functionality would ordinarily be expected to decreaseas the fatty acid content increases.

It has also been discovered that the compounds of the present inventionin free acid form and containing an average of less than 1 lactyl groupper molecule are much more stable than those materials in free acid formhaving an average number of lactyl groups per molecule of greaterthan 1. The greater stability of the free acid forms of ice thematerials taught herein permit their use in products requiring a longshelf life, such as, for example, dry cake mixes.

Lactic acid suitable for preparing the acyl lactylic acid compositionsdescribed herein may be and usually is an aqueous solution of lacticacid. Technical grades are available in which the lactic acidconcentration varies from about 20 to 80 percent.

The stronger acids are generally prepared by concentration of theaqueous solution under vacuum to avoid decomposition.

In preparing the acyl lactylic acid compositions suitable for use in thepresent invention, free water may be removed from the lactic acidaqueous solutions by heating the solutions at temperatures below about98 C., and preferably below 90 C., under vacuum. Care should be taken inheating to insure that the temperature does not get higher than about100 C., at which temperature lactic acid either is converted to theanhydride, or polymerizes to polylactylic acid. Polymerization oranhydride formation will occur to a limited extent even at temperaturesas low as 100 C., but this is not serious.

The progress of the polymerization during dehydration of the lactic acidaqueous solutions can be followed by titration of samples withdrawn fromthe reaction vessels. If the samples are saponified, the amount of freewater present may also be calculated.

When a dilute solution of lactic acid is concentrated, two molecules oflactic acid condense to form one molecule of lactyllactic acid and freeone molecule of water. When the solution is further concentrated byheating, one molecule of lactyllactic acid loses a molecule of water toform one molecule of lactide. The mechanisms of these reactions arebelieved to be as follows:

2GH OHOHC O OH CH3CHOHOO O CH(OH COOH H2O OH(OH COOCH(GH3) C O O H 0Chain polylactyllactic acids also may be formed through successive lossof water between the carboxyl and alcohol groups. The formula ofdilactyllactic acid is:

OH CHOHCOOH CHCOCH OHCOOH When concentrated acids are subjected totemperatures in excess of 100 to 110 C., the lactic acid is convertedgradually to di-, tri-, tetra-, penta-, and other polylactyllacticacids.

As will be seen, aqueous solutions of lactic acid actually contain amixture of a number of compounds: monomeric lactic acid, lactyl lacticacid, higher polymers of lactic acid, lactide and water.

It is obvious that such a complex mixture cannot be analyzed by merelyone criterion, such as free acid titration.

For purposes of producing the acyl lactylic acid products of the presentinvention, it is desirable to use lactic acid which has been dehydratedin such a manner as to insure minimum polymerization, i.e., minimumformation of polylactyllactic acid and polymeric lactic acid.

This is best done by using low temperatures and an entraining fluid asdescribed in Industrial Engineering and Chemistry, vol. 32, No. 3, pp.399-401 (1940).

According to the procedure described in the cited article, concentratedlactic acid is produced by distillation of the technical grades oflactic acid containing 20 to percent or more by weight of water in thepresence of liquids which form binary mixtures with water, i.e.,azeotropic mixtures, which distill at temperatures below the boilingpoint of the acid, and preferably below about 100 C., or below about to98 C.

Following this procedure, the water is readily removed and leaves aresidue of more or less anhydrous acid with total acidity of 100 percentor more. Care should be employed to insure that the entraining liquid isimmiscible with water so that it may be readily separated and recycled.

Suitable for use as the entraining liquid may be mentioned alkylhalides, such as tetrachloroethylene, trichloroethane, carbontetrachloride, ethylene dichloride, methylene chloride, ethyl chloride,butyl chloride and propylene chloride; aromatic hydrocarbons such asbenzene and toluene; and lower boiling hydrocarbons of the alkane,alkene, or alkine series, such as heptane, petroleum ether, and thelike. If desired, mixtures of two or more liquids having the propertiesdescribed may be used as the entraining fluid.

Preferably, the entraining liquid is such that it forms an azeotropicmixture with water that boils below about 100 C., and preferably belowabout 90 C., or between about 30 and 90 C. l

The method of carrying out the concentration procedure will be clearfrom the following example:

EXAMPLE A An aqueous solution of lactic acid containing 50 percent byweight of lactic acid as CH CHOHCOOH is placed in a still together withan excess of benzene. The mixture is heated to a temperature of 76 to 82C., at which temperature a binary mixture of water and benzene distillsoff. The distillate is continuously condensed and the benzene fractionthereof separated from the distillate and continuously recycled to thestill. Distillation is continued over the indicated temperature rangeuntil no further distillate comes off.

The analysis of the product 4 days after preparation is as follows:

Weight percent Total acidity 101.92 Lactic acid 66.3 4 Lactyl-lacticacid 3 2.02 Lactide 0.0

Water 1.64

Following this procedure, concentrated lactic acid having the followingcompositions may readily be obtained and is preferred for use inpracticing the present invention:

Weight percent Total acidity 100 to 108 Lactic acid 1 to 67Lactyl-lactic acid 32 to 95 Lactide to 6 Water 0 to 6 When dehydrationof technical grades of lactic acid are carried out as indicatedhereinabove, the concentrated product will have an equivalent weight ofbetween 95 and 130, based on free titratable acidity.

The concentrated lactic acid prepared as indicated hereinabove withdistillation temperatures of less than about 100 C. containssubstantially no polylactyllactic acid. Thus, the amount ofpolylactyllactic acid in the concentrate is generally less than percent,and usually less than 3 percent, or between about 0 and 3 percent byweight.

Concentrated lactic acid thus prepared, when reacted with an equimolarquantity of an acyl chloride under specially controlled conditions, aswill be made clear hereinbelow, results in a product in which theaverage number of lactyl groups per molecule is less than 1. Incontrast, lactic acid dehydrated at high temperatures produces a producthigh in polymeric lactic acid which is unsuitable for use in the presentinvention.

In lieu of using aqueous solutions, lactic acid in dry powdered form,and having an average equivalent weight within the indicated range mayalso be used. Such dry lactic acid compositions have only recentlybecome commercially available.

To prepare the acyl lactylic acid compositions described herein, lacticacid, suitably prepared as indicated above, is reacted with acylderivatives of the fatty acids of commerce, such as acyl halides, andmore particularly acyl chlorides. The esterification reaction proceedsat room temperature, but for purposes of speed, the reaction mixture maybe heated to temperatures of about 50 C. to 95 C., and preferablybetween about 65 and C. Particularly good results are obtained at 70 C.,and this temperature appears to be optitmum. Vacuum removal of gaseousproducts is not employed until the end of the reaction.

The fatty acid halides employed may be prepared using conventionalmethods from fatty acids containing 16 to 24 carbon atoms, or from fattyacid mixtures predominantly containing such fatty acids, as for examplefatty acid mixtures derived from naturally occurring fats and oils.Preferably, the fatty acids are all reacted with phosphorous trichlorideor thionyl chloride to produce the acyl chlorides. By using lowtemperatures, retaining a maximum of the by-product HCl throughout thereaction, and starting the reaction with a minimum of the fatty acid,anhydride formation is reduced to a minimum.

The manner of forming the acyl monohydroxy monocarboxylic acidsdisclosed will be clear from the following examples which, althoughillustrative, are not intended to limit the scope of the invention,except as such limitations may appear in the claims.

EXAMPLE 1 Lactic acid was carefully dehydrated by the benzene entrainingmethod of Example A to an equivalent Weight (based on free titratableacidity) of 115. A pure grade of stearyl chloride was made by standardprocedures using the special precautions previously mentioned.Equirnolar quantities (based on the equivalent weight calculated fromthe free titratable acidity of the lactic acid) were used. One mole ofthe stearyl chloride was placed in a reaction flask and heated to 50 C.A mole of the lactic acid was added slowly, with stirring, over aforty-five minute period. During the forty-five minutes, the temperaturewas gradually raised to 70 C. The mixture was kept at this temperaturefor ninety minutes. Vacuum was then applied to remove the HCl gasproduced, and maintained twenty minutes after the bubbling ceased. Theproduct was washed four times by shaking with a liter of C. distilledwater in a separatory funnel, and dried in a vacuum dessicator. Theproduct equivalent weight, based on free titratable acidity, was 340,indicating an average number of lactyl groups per molecule ofapproximately 0.77. The reaction material was a honey-colored plasticsolid with a distinct lipoidal character and had melting range of 51-53C.

EXAMPLE 2 Lactic acid was carefully dehydrated by the benzene entrainingmethod of Example A to an equivalent weight (based on free titratableacidity) of 130. Equirnolar quantities of lactic acid and stearylchloride were used. The reaction was carried out, as described inExample 1. The product had an equivalent weight of 350, indicating anaverage number of lactyl groups per molecule of 0.91.

EXAMPLE 3 Lactic acid was carefully dehydrated by the benzene entrainingmethod of Example A to an equivalent Weight (based on free titratableacidity) of 105. Equirnolar quantities of lactic acid and stearylchloride were used, the reaction conditions being identical to those inExample 1. The product had an equivalent Weight of 325, indicating anaverage number of lactyl groups per molecule of 0.56.

EXAMPLE 4 The reaction was carried out as in Example 1, except palmitylchloride was used instead of stearyl chloride.

The resulting product had an equivalent weight of 312, indicating anaverage number of lactyl groups per molecule of 0.77.

EXAMPLE 5 Hydrogenated fish oil fatty acids having the followinganalysis:

were treated with an equimolar quantity of thionyl chloride for twohours to prepare the mixed acyl chlorides, and the excess thionylchloride was removed by warming the mixture at 90l00 C. for severalhours.

The acyl chloride mixture is substituted in the process of Example 1.The average equivalent weight of the product based on free titratableacidity of 342 indicated an average number of lactyl groups per moleculeof 0.75.

To prepare the salts of the acyl lactylic acids, the acids may bedissolved in a suitable solvent, such as absolute alcohol, and a smallquantity of Water, e.g., 1 to percent by weight, together with salts ofthe desired cation, added. Typical salts include the carbonates,bicarbonates, hydroxides, and other salts of alkali and alkaline earthmetals, aluminum and ammonium. Following admixture, the solvent isremoved by vacuum desiccation to obtain the anhydrous salts.

Using this procedure, preferred salts having an average of less than 1lactyl group per molecule have been prepared by using sodiumbicarbonate, potassium carbonate, calcium carbonate, magnesiumcarbonate, aluminum chloride and ammonium hydroxide.

The fatty acid lactylic acids and salts thereof having an average numberof lactyl groups per molecule of less than 1, and perferably betweenabout 0.3 and 0.9, have surprising functionality as emulsifiers andmodifiers of protein and starch materials when added as ingredients orin combination with ingredients of baked leavened goods.

The acid form of these materials, as has been brought out, is morestable than the acid form of materials in which the number of lactylgroups per molecule is greater than 1.

Thus, the free acid form of the materials of the present invention canbe used in prepared cake mixes, or in shortening used to prepare cakesor other sweet leavened products. The resulting mixes and/or shorteningcompositions have extremely long shelf life, and the presence of theacyl lactylic acid in free acid form leads to marked improvement in thephysical properties of the cake.

Shortenings or oils with which the acyl lactylic acids disclosed hereinmay be mixed are of the usual type, and are, in general, triglycerideoils or fats derived from animal sources such as lard or tallow and fromplant sources such as the seed oils or corn, cotton, soy and the like.It is normal to improve their properties. The usual treatments includecatalytic hydrogenation to improve the plasticity, increase hardness andreduce the iodine number of the fatty material and heat treatment in thepresence of alkaline catalysts, with or without added glycerine, toimprove the' physical properties and functionality. For instance, theplastic superglycerinated vegetable shortenings have been hydrogenatedand subjected to interesterification reactions to improve the physicalcharacteristics and increase the emulsification properties of theshortening. Shortenings of the usual type may also contain glycerineand/ or lecithin.

The acyl lactylic acids may be incorporated into the base oil by meltingthe shortening, or oil, and dissolving therein a small quantity of theacyl lactylic acid, and then carefully stirring and tempering theresultant mixture. Final treatment may also include the chilling andwhip- 6 ping treatments of the Votator process in the case of plasticshortenings.

The quantity of acyl lactylic acids imparting optimum functionality tothe shortening compositions varies some- What dependent upon the natureof the usual type shortening employed as the basic shortening materialbut has been found empirically to be within a rather narrow range ofabout 3% or less by weight. However, good results are also obtained withquantities ranging from about 0.5 to 5%. Obviously, however,combinations of the usual shortenings and larger amounts of the acyllactylic acids can be produced and used in lieu of only a portion of theusual shortening with the same net functional benefits resulting, andsuch compositions are to be considered to be a part of this invention.

The functionality of the improved shortening compositions according tothe invention in cake is superior to the usual type shortenings fromwhich they are, in part, compounded. They provide for improved batteraeration and stability which results in cakes of notably improvedvolume, symmetry, and grain characteristics. The cakes obtained aredesirably tender or short and have superior eating and keepingqualities. In addition the use of the improved compositions makes itmuch easier to prepare a satisfactorily balanced formula for a highratio prepared dry cake mix.

The cake mixes according to the invention can be prepared, for example,by thoroughly blending together the usual mix ingredients, such asflour, baking powder and sugar, with the improved shorteningcomposition; preferably the shortening composition is blended with thedry ingredients of such a mix before addition of liquid ingredients,such as water, milk, eggs, fiavorings and the like.

Regardless of whether the acyl lactylic acid is added as a separateingredient, or in combination with the shortening, the amount of acyllactylic acid will generally range between about 0.1 and 5%, andpreferably less than 3%, by Weight, based upon the Weight of shorteningin the formula. However, certain speciality applications such as in thepreparation of icings and fondants place greater demends on thefat-water emulsification and levels ranging from 5 to 10% based on theshortening weight have proven beneficial.

The surprising functionality of the acyl lactylic acids containing lessthan 1 lactyl acid group per mole, as compared to acyl polylactylicacids in which the number of lactyl groups per mole is greater than 1,is shown by the following examples:

EXAMPLE 6 Stearyl lactic acid preparations made according to theprocedure of Example 1 and containing an average of 0.56, 0.77, and 0.91lactyl groups per molecule, respectively, were admixed with a purehydrogenated vegetable oil shortening and the resulting shortenings werecompared in the following cake formulation:

52.7 percent of the total Water is added to the dry mix over a oneminute period at first speed using a Hobart N-SO mixer. The bowl isscraped down and mixed two minutes at first speed. The liquid egg whitesare added over a one minute period at first speed, after which the bowlis scraped down again and the contents mixed twoand-one-half minutes atsecond speed. The remainder of the water (47.3%) is added over a oneminute period at first speed, followed by scraping of the bowl andmixing three minutes at first speed.

The resulting batter, at a temperature of 7278 F., is poured into 8"layer cake pans, 368.5 grams to the pan, and baked for 24-26 minutes at375 F.

The results of the comparative bake tests are tabulated in Table I. Inthe tables, A.I.B. method quality score refers to the American Instituteof Baking system devised to measure the quality of baked leavened goods,and is a summary of the factors of symmetry, volume, crust, crumb color,grain, texture, flavor and aroma and eating quality. Also in the tables,comparative volumes were determined by rape seed displacement.

Table l Batter, Cake Quality Shortening Sp. Gr. Volume Score Control1.06 530 85 2.5% Stearyl 0.56 Lactylic Acid 0. 84 575 96 2.5% Stearyl0.77 Lactylic Acid 0. 78 600 99 2.5% Stcryl 0.91 Lactylic Acid... 0.81585 98 It is obvious from the above table that the average number oflactyl groups per molecule is an important factor in the degree offunctionality of the acyl lactic acids and that the functionalityapproaches optimum between 0.77 and 0.91 lactyl groups per molecule onthe average.

The following example demonstrates the improved storage stability ofacyl lactylic acids containing minimal amounts of polymeric lactic acidcombined with prepared mix ingredients.

EXAMPLE 7 Dry mixes containing the acyl lactylic acids cited in Table IIare stored over a period of six months. After two, four, and six months,cake is prepared from the dry mixtures using the procedure of Example 6.The level of acyl lactylic acid in the shortening is held constant at 3%of the shortening weight. The results of these tests are summarized inTable II. In the tests, the stearyl 0.77 lactylic acid and stearyl 0.56lactylic acid were prepared using the procedure of Examples 1 and 3respectively.

As can readily be seen from Table II, when the average number of lactylgroups per molecule is less than 1, the cake mixes had greatly improvedstorage stability, as compared with the cake mixes containing acylpolylactylic acids having more than one lactyl group per molecule.

To further demonstrate the marked improvement of acyl lactylic acidscontaining less than one lactyl group per molecule, the followingexperiment is presented. To be stable in storage when used as aningredient in chemically leavened cake premixes containing baking soda,the acyl lactylic acid composition must not contain strong Water solubleacids such as lactic acid, and must not yield acidic components oncontact with moisture. Thus the following test is indicative of storagestability.

pH Stearyl 0.56 lactylic acid 3.4 Stearyl 0.77 lactylic acid 3.3 Stearyl0.91 lactylic acid 3.1 Stearyl 1.20 lactylic acid 2.8

Thus stability in storage increases as the number of lactyl groups permolecule decreases.

The difference between stearyl lactylic acid compositions with anaverage number of lactyl groups of less than one and those with anaverage of more than one is clearly illustrated in the following twocompounds which have been analyzed chromatographically.

Lactyl groups/molecule 1.20 0.81 Component Fraction I 24.97 21. 47Stearic Acid. Fraction II 38. 57 68. 27 Stearyl Monolactie Acid.Fraction III. 19. 97 8.07 Stearyl Dilactic Acid. Fraction IV- 7. 97 0.67 Stearyl Polylactic Acid. Fraction V- 8. 47 1. 87 Polylactic Acid.

It is readily seen that the two composition mixtures are distinctlydiflerent, one containing insignficant amounts of polylactic material(Fractions IV and V), the other a very high percent of the same.

In addition to use in cake mixes and shortening, the materials of thepresent invention both in free acid and salt form, have been found tohave a marked effect on the gelation temperature of starch and themixing character of bread flour, particularly when the materials areused in salt form. This eifect is greatly accentuated when the averagenumber of lactyl groups per molecule is less than one.

In using the materials disclosed herein and containing less than onelactyl group per molecule in yeast leavened baked goods, the materialsmay be admixed with the flour, or may be added separately to the mixtureused to produce the baked products. Alternatively, the material can bemixed with other ingredients and in this way incorporated into theformula. In any event, the acyl lactylic acid compositions disclosedherein lead to physical improvement of the proper-ties of the flour,regardless of whether they are added in intimate admixture with theflour itself, or added to the baked leavened dough product as separateingredients, or in admixture with other ingredients.

Preferably, the acyl lactylic acid compositions containing less than onelactyl group per molecule are admixed with the flour to provide new anduseful flour compositions for use in baked leavened goods.

Regardless of how added, the amount of the acyl lactylic acidcompositions may vary up to about 5% by weight of the flour, althoughusually between about 0.1 and 1% by weight of the fiour will besufiicient.

When added to the flour, mixtures of flour and the acyl lactylic acidcompositions containing from about 1 to 99 percent by weight acyllactylic acid compositions may be prepared. Such a mixture may then beused as a substitute for flour or in lieu of a portion of the flour, aswill readily be understood.

The mixing characteristics of a flour and the quality of the bakedproducts obtained therefrom, are determined to a very large extent bythe colloidal properties of the proteinaceous component. An instrumentcalled the Farinograph is conventionally employed in the art todetermine the characteristics of the flour, and the data obtained fromthis instrument have been demonstrated to correlate with the conditionswhich must prevail in a bakery if products of optimum quality are to beobtained. This procedure is now Well established for yeast leavenedproducts. Although the data obtained have also been used to predict theperformance of flour in batters, the exactitude of correlation is not sowell established as with yeast leavened products. The operation of theFarinograph is well understood in the art and is described, for example,in United States Patent 2,744,826.

The Farinograph is essentially a miniature, low speed, recording mixerand provides three measurements on a flour which are of value inestablishing the characteristics of the flour, predicting its bakingperformance and permitting procedural alterations to allow for thevariables. By placing a specified amount of flour in the bowl andtitrating, the amount of water required to give a paste of standardconsistency is determined. This titration figure, called absorption,will vary from 50 to 65 percent for normal flours. A time value, calledmixing time or peak time, is indicated by the time required to developthe gluten colloid in the paste and to reach a standard maximumviscosity with mixing. The measure, called mixing tolerance index orMTI, is the change in paste viscosity in the units of measure caused bybreakdown or dispersion of the gluten colloid five minutes after themaximum or peak viscosity is reached. The MTI is a reciprocal functionof tolerance to mixing and handling; tolerance increases as MTIdecreases.

The Farinograph data are of value to the baker in establishing mixingtime and absorption optirnums for a flour used in making yeast leavenedproducts, but the action of the high speed commercial mixers is suchthat actual attainment of an optimum mix is very difficult and sometolerance in this respect is very important. In baking practice theflour used in this kind of product is a strong flour, with high glutencontent, usually somewhat more than Flours with a low MTI are desirable;one with an MTI of 40-50 will lead to production difiiculties because itlacks tolerances. Flours with an MTI over 50 will be rejected by manybakers.

Confectioners flours of the types used in cakes, cookies, pie doughs,doughnuts, and the like, usually are of finer granulation and morehighly bleached. They are made from soft wheats of widely varying typesbut, in general, have a protein content of about 8% which is of a weakor very extensible type. If the protein is too high, the baker expects abatter product, such as cakes, to be of tough consistency, although theflour might make fine cookies. Taking into account the protein contentrequired to give a particular batter product, the more extensible thegluten, the better the product. The tolerance measurement provided bythe Farinograph is correlated with extensibility, which will determinethe cellular crumb structure and eating quality of the finished product.

EXAMPLE 8 To demonstrate the action of acyl lactylates in themodification of the mixing properties of wheat flour, acyl lactylateshaving varying n values are compared directly. The Barbender Farinographwith large bowl is used in the preparation of mixing curves. Farinogramsare prepared using 300 g. of flour on a 14% moisture basis.

The acyl lactylic acids tested were combined with the flour in the formof a 50% by Weight hydrate. The Water employed in preparing the aqueousform was taken into consideration in reporting the absorption.

After the normal absorption required to give a pea viscosity of 500 B.U.is determined by titration, this quantity of water is kept constant forthe remainder of the mixing test. The two criteria, mixing time andmixing tolerance index, are obtained by interpretation of the curves.

The results obtained using this method are summarized in Table III.

This data shows that the stearyl 0.69 lactylic acid at the levels usedhas a pronounced ability to increase mixing' tolerance. The improvementis significantly greater than that found when the acid form of stearyl1.15 lactylate was tested. The changes found in mixing, or peak time,confirm the improved effect of the acyl lactylate in which the averagenumber of lactyl groups per molecule is less than one.

As indicated above, flour with low MTI is known to be the mostdesirable. The significance of the variations of apparent mixing timeare not definitely understood, however smaller values have been found tocorrelate with greater functionality of an acyl lactylic acidpreparation due to greater retardation of the rate of hydration ofstarch, a known effect of acyl lactylate compounds.

The materials disclosed herein, both in free acid form as well as insalt form, not only improve the overall quality of bread and other bakedleavened products, but also substantially improve the retention of thesoft character of the baked leavened products during aging and thereforeretard the apparent staling of such products. So far as staling isconcerned, the eifect of the materials having an average number oflactyl groups per mole of less than one show much greater anti-stalingeffects than do the acyl polylactylic acid compositions having anaverage of more than one lactyl group per molecule. The comparison isabout in the same relationship as that indicated in Example 8.

The particular ingredients employed in making the baked leavenedproducts described hereinabove form no part of the present inventionsince any suitable formulae for the baked goods may be used. The basicingredients used in the manufacture of bread, for example, are flour,water, sodium chloride and yeast. For commercial bread, sugar, milk,shortening and a suitable emulsifier for the shortening, such asglycerides, are conventionally added to these basic ingredients, and thepresent invention is particularly suitable with bread formulaecontaining such additional ingredients. For cake, or other sweetleavened products, eggs as well as other enriching agents may also beadded. Ordinarily, in making cake, chemical leavening agents, such asbaking powder, rather than yeast, are employed.

The invention in its broader aspects is not limited to the specificcompositions, steps and methods described, but departures may be madetherefrom within the scope of the accompanying claims without departingfrom the principles of the invention and without sacrificing its chiefadvantages.

What is claimed is:

1. A composition of matter comprising flour in intimate admixture withan acyl lactylic acid composition corresponding to the formula:

RCO (OCHCH CO OZ wherein RC0 is a member selected from the groupconsisting of acyl radicals of fatty acids containing 16 to 24 carbonatoms and mixtures thereof, It is a number ranging from about 0.3 toabout 0.9 which represents the average number of lactyl groups presentper molecule and Z is a cation selected from the group consisting ofsodium, potassium, calcium, magnesium, ammonium, aluminum, and hydrogen.

2. A cake mix comprising flour, baking powder, sugar,

shortening, and 0.1 to 5% by weight, based on the weight of shortening,of an acyl lactylic acid composition corresponding to the formula:

RCO (OCHCH CO OZ wherein RC0 is a member selected from the groupconsisting of acyl radicals of fatty acids containing 16 to 24 carbonatoms and mixtures thereof, n is a number ranging from about 0.3 toabout 0.9 which corresponds to the average number of lactyl groupspresent per molecule and Z is a cation selected from the groupconsisting of sodium, potassium, calcium, magnesium, ammonium, aluminum,and hydrogen.

3. A composition of matter comprising shortening and an acyl lactylicacid composition of the formula:

RCO (OCHCH CO OZ wherein RC0 is a member selected from the groupconsisting of acyl radicals of fatty acids containing 16 to 24 carbonatoms, and mixtures thereof, n is a number ranging from about 0.3 toabout 0.9 which represents the average number of lactyl groups permolecule and Z is a cation selected from the group consisting of sodium,potassium, calcium, magnesium, ammonium, aluminum, and hydrogen.

References Cited in the file of this patent UNITED STATES PATENTS2,744,825 Thompson et a1 May 8, 1956 2,744,826 Thompson et al. May 8,1956 2,943,270 Thompson et al. Feb. 28, 1961

1. A COMPOSITION OF MATTER COMPRISING FLOUR IN INTIMATE ADMIXTURE WITHAN ACYL LACTYLIC ACID COMPOSITION CORRESPONDING TO THE FORMULA: